Generally, hot stamping is a method in which a steel material heated to the high temperature of 950° C. is put in a mold and is subjected to press molding and rapid cooling in the mold, and is used to produce a high strength component through heating a material to high temperature by a panel molding method which molds a steel sheet under the high temperature condition to make a car body that reduces in weight while maintaining stiffness, and then through press molding and cooling a mold itself.
The mold used in hot stamping is referred to as a hot stamping mold, and a cooling block having channels through which cooling water passes is provided within the hot stamping mold.
According to the related art, Korean Patent No. 10-0907266 (a mold for forming a hot stamping material), the mold for forming a hot stamping material is provided to fabricate cooling channels for cooling a mold used in molding a steel sheet under the high temperature condition in a simple and convenient manner in order to improve fuel efficiency of vehicles, characterized by including a mold having grooves on a surface opposite to a contact surface with a product, tubular cooling water channels inserted into the grooves, and an insulating member installed on the surface of the mold to bury the cooling water channels, wherein the grooves are formed on one side of the mold at equal intervals, into which each of the plurality of cooling water channels is inserted, and the insulating member has spacing plates to support both sides of the cooling water channels, the spacing plates protrusively formed to be inserted into the corresponding grooves.
According to another related art, Korean Patent No. 10-1317414 (a mold for hot stamping and a manufacturing method thereof), the mold for hot stamping and its manufacturing method includes: a base plate configured to receive and exhaust a coolant through a nipple mounted on one side; at least one exterior mold mounted on one surface of the base plate and formed in a same shape as an external shape of a product to form the external shape of the product during hot stamping, and having a mounting space inside; and an insert block coupled to the exterior mold while being inserted into the mounting space of the exterior block to allow the coolant to flow to the mounting space, and mounted between the base plate and the exterior block to allow the coolant having flowed in through the base plate between the base plate and the exterior block to flow on the mounting space of the exterior block, and claim 10 recites a method of manufacturing a mold for hot stamping including: preparing a lower mold and an upper mold with different materials and working insides of the lower mold and the upper mold; disposing the upper mold on the lower mold of which the insides were worked and performing diffusion jointing by applying pressure to the lower mold and the upper mold together at the temperature below the melting point of each mold; rough grinding appearances of the lower mold and the upper mold assembled through the above step; after the appearance processing is completed, heat-treating the assembled lower mold and upper mold; after the heat-treating of the assembled lower mold and upper mold is completed, assembling the heat-treated lower mold and upper mold to a base plate; and after the mounting on the base plate is completed, finishing appearances of the assembled lower mold and upper mold, wherein diffusion jointing at the diffusion jointing step of the lower mold and the upper mold is performed in a vacuum, and a diffusion layer is formed between contacting surfaces of the lower mold and the upper mold, and the lower mold and the upper mold are thereby assembled.
However, the traditional molds such as the above are prone to corrosion due to cooling water, and have low cooling efficiency.